jQuery.fn.rotate = function(angle,whence) {
    var p = this.get(0);

    // we store the angle inside the image tag for persistence
    if (!whence) {
        p.angle = ((p.angle==undefined?0:p.angle) + angle) % 360;
    } else {
        p.angle = angle;
    }

    if (p.angle >= 0) {
        var rotation = Math.PI * p.angle / 180;
    } else {
        var rotation = Math.PI * (360+p.angle) / 180;
    }
    var costheta = Math.cos(rotation);
    var sintheta = Math.sin(rotation);

    if (document.all && !window.opera) {
        var canvas = document.createElement('img');

        canvas.src = p.src;
        canvas.height = p.height;
        canvas.width = p.width;

        canvas.style.filter = "progid:DXImageTransform.Microsoft.Matrix(M11="+costheta+",M12="+(-sintheta)+",M21="+sintheta+",M22="+costheta+",SizingMethod='auto expand')";
    } else {
        var canvas = document.createElement('canvas');
        if (!p.oImage) {
            canvas.oImage = new Image();
            canvas.oImage.src = p.src;
        } else {
            canvas.oImage = p.oImage;
        }
        
        //canvas.style.width = canvas.width = Math.abs(costheta*canvas.oImage.width) + Math.abs(sintheta*canvas.oImage.height);
        //canvas.style.height = canvas.height = Math.abs(costheta*canvas.oImage.height) + Math.abs(sintheta*canvas.oImage.width);
        canvas.style.height =canvas.height = p.height;
        if(p.height<p.width)
        {
            var as=p.width/p.height;
            canvas.style.width =canvas.width= p.height/as;
        }
        else if(p.height>p.width)
        {
            var as=p.height/p.width;
            canvas.style.width =canvas.width= p.height*as;
        }
        else
        {
            canvas.style.width =canvas.width= p.width;
        }
                
        var context = canvas.getContext('2d');
        context.save();
        if (rotation <= Math.PI/2) {
            context.translate(sintheta*canvas.oImage.height,0);
        } else if (rotation <= Math.PI) {
            context.translate(canvas.width,-costheta*canvas.oImage.height);
        } else if (rotation <= 1.5*Math.PI) {
            context.translate(-costheta*canvas.oImage.width,canvas.height);
        } else {
            context.translate(0,-sintheta*canvas.oImage.width);
        }
        context.rotate(rotation);
        context.drawImage(canvas.oImage, 0, 0, canvas.oImage.width, canvas.oImage.height);
        context.restore();
    }
    canvas.id = p.id;
    canvas.angle = p.angle;
    p.parentNode.replaceChild(canvas, p);
}

jQuery.fn.rotateRight = function(angle) {
    this.rotate(angle==undefined?90:angle);
}

jQuery.fn.rotateLeft = function(angle) {
    this.rotate(angle==undefined?-90:-angle);
}
